JP2000306709A - Rheostat - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rheostat which can increase voltage change width. SOLUTION: First to fourth resistors 61-64 and first to sixth conductors 65-70 are printed on a PC board 2 of a rheostat. The first to fourth resistors 61-64, the second to fourth conductors 66-68, a bend part 65b of the first conductor 65 and a bend part 69b of the fifth conductor 69 are printed on the same circle. A ring part 72 of the sixth conductor 70 is annular. A first sliding part of a sliding member slides along the ring part 72, and a second sliding part slides along a virtual circle formed by the first to fourth resistors 61-64. In each of the ranges in which an operation angle is 0-θ1, θ2-θ3, θ4-θ5, θ6-θ7 and θ8-θ9, a voltage ratio is constant. In each of the ranges, in which the operation angle is θ1-θ2, θ3-θ4, θ5-θ6 and θ7-θ8, the voltage ratio changes. Since the ranges where the voltage ratio becomes constant are arranged, the voltage change width can be increased in the ranges (especially in θ5-θ6), except for the ranges of a constant voltage ratio.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rheostat.

[0002]

2. Description of the Related Art Conventionally, a rheostat capable of outputting a potentiometer for dimming a dimming lamp is known, and this dimming function is further combined with an on / off switch for turning on / off another lighting lamp in a vehicle. Rheostats are also known.

The latter requires the provision of a volume section for potentiometer output and an on / off switch section. Therefore, instead of the on / off switch section, only the output (voltage) of the volume section is used to set the on / off switch mode. There is also proposed a rheostat for switching between a dimming mode and a dimming mode.

FIG. 8 shows a PC board used in the above rheostat. A fitting hole 103 is formed in the center of the PC board 101. PC board 10
A resistor 104 is printed on the surface of the first member 1 along a circle centered on the fitting hole 103. PC board 1
01 are provided with first to third connection terminals 105 to 107.

[0005] A first conductor 108 is provided between the first connection terminal 105 and the starting end of the resistor 104, and the first conductor 108 electrically connects the first connection terminal 105 and the resistor 104. ing. On the other hand, the third connection terminal 107
A second conductor 109 is provided between the second conductor 109 and the terminal of the resistor 104, and the third connection terminal 1 is provided by the second conductor 109.
07 and the resistor 104 are electrically connected. or,
On the surface of the PC board 101, a third conductor 11 having a ring portion 110 arranged so as to surround the fitting hole 103 is provided.
1 is printed, and the third conductor 111 is electrically connected to the second connection terminal 106.

The rheostat has an operating member (not shown), and the operating member is rotatably supported on the PC board 101 about the fitting hole 103 as a center of rotation. The operation member includes a first sliding portion that slides on the ring portion 110 of the third conductor 111, and the resistor 104
A conductive sliding member having a second sliding portion that slides on the conductive member; Then, when the operation member is rotated, the second
The first connection terminal 105 and the second connection terminal 105 are based on the contact position of the sliding portion.
A voltage between the connection terminal 106 and the connection terminal 106 is input to a dimming control circuit (not shown), and based on the voltage, the dimming control circuit performs on / off control of a lighting lamp in the vehicle or dimming control of the dimming lamp.

FIG. 9 is a characteristic diagram showing the relationship between the operation angle θ of the rheostat and the voltage ratio V. First, the operation angle θ of the operation member when the first and second sliding portions of the operation member are arranged on the reference line α0 shown in FIG. here,
The reference line α0 is a straight line passing through the center R of the fitting hole 103 of the PC board 101 and the start end of the curved portion of the first conductor 108. In FIG. 8, on the reference line α0, the position of the first sliding portion is indicated by reference symbol S0, and the position of the second sliding portion is indicated by reference symbol T0.

In FIG. 8, first and eighth virtual lines α
1, α8 are straight lines passing through the center R and the start and end of the resistor 104, respectively. The ninth virtual line α9
Is a straight line passing through the center R and the end of the curved portion of the second conductor 109. Furthermore, the second to seventh virtual lines α2 to α7
Are straight lines passing through the center R and a position on the resistor 104, respectively. Further, on the first to ninth virtual lines α1 to α9, the positions of the first sliding portions are indicated by reference numerals S1 to S9, and the positions of the second sliding portions are indicated by reference numerals T1 to T9. Further, angles formed by the reference line α0 and the first to ninth imaginary lines α1 to α9 are θ1 to θ9, respectively.

Now, if the operation angle θ is in the range of 0 to θ1,
The electric resistance between the first connection terminal 105 and the second connection terminal 106 is substantially zero, and the voltage input to the dimming control circuit is zero. Next, when the operation angle θ is in the range of θ1 to θ8,
As the electric resistance increases, the voltage ratio V of the voltage input to the dimming control circuit linearly changes from 0 to V17.
Note that the voltage ratio V corresponding to the electric resistance value from the beginning to the end of the resistor 104 is V17 (the voltage ratio V is 100%). Next, when the operation angle θ is in the range of θ8 to θ9, the voltage ratio V becomes V17.

When the voltage ratio V is 0, the dimming control circuit turns off the dimming lamp. Note that the operation angle θ is 0
The range from to θ1 is defined as a first switch region. Also, the voltage ratio V
Is in the range of V11 to V12, the dimming control circuit:
Only the illumination lamp A is turned on. Note that the operation angle θ is θ2
The range from to θ3 is defined as a second switch region.

Further, when the voltage ratio V is in the range of V13 to V14, the dimming control circuit controls the dimming of the dimming lamp so that the brightness of the tuning dimming lamp becomes the darkest. The range in which the operation angle θ is θ4 to θ5 is defined as a third switch area. Further, when the voltage ratio V is in the range of V15 to V16, the dimming control circuit performs dimming control on the dimming lamp so that the brightness of the tuning dimming lamp becomes the brightest. The range in which the operation angle θ is θ6 to θ7 is defined as a fourth switch area.

Here, when the voltage ratio V is in the range of V14 to V15, the dimming control circuit controls the brightness of the dimming lamp based on the value of the voltage ratio V. Specifically, the voltage ratio V
As V approaches V15 from V14, the dimming lamp is turned on so that it gradually becomes brighter. The range in which the voltage ratio V is from V14 to V15 is defined as a rheostat variable region.

When the voltage ratio V is V17, the dimming control circuit turns on the dimming lamp in the brightest state and turns on the illumination lamp B. The range in which the operation angle θ is θ8 to θ9 is defined as a fifth switch area.

[0014]

However, in the conventional rheostat, the voltage ratio V is displaced by the displacement of the operation angle θ in the second to fourth switch regions. That is, although the voltage ratio V should be constant in the on / off switch section, the voltage ratio V is displaced in the rheostat. Therefore, in the potentio output rheostat in which the operation angle is limited, the rheostat variable region is not changed. It becomes narrow. In general, in such a potentio output rheostat, the angle tolerance such as the printing deviation of the resistor is about ± 10 degrees. Therefore, taking this angular tolerance into account, the rheostat variable region is further narrowed.

As described above, when the rheostat variable region becomes narrow, the voltage ratio (resistance value) per unit operation angle becomes large, and the voltage ratio becomes unstable, and the error of the voltage ratio becomes large. This problem is particularly noticeable in rheostats having a large resistance value.

An object of the present invention is to provide a rheostat capable of widening a voltage change width.

[0017]

According to a first aspect of the present invention, there is provided a variable resistor portion, which is slidably contacted with the variable resistor portion, and which receives an output voltage from the variable resistor portion by an external operation. The variable resistance section comprises a plurality of resistors having a plurality of predetermined resistance values, and a conductor electrically connected between the resistors. The gist is that the slider slides including the conductor provided between the resistors and the resistor.

Therefore, according to the first aspect of the invention, when the slider slides on each resistor and the conductor provided between the resistors, the output voltage changes according to the sliding contact position of the slider. That is, in the range where the slider slides on the resistor, the output voltage changes in accordance with the resistance value at the sliding contact position, and the output voltage becomes constant in the range where the slider slides on the conductor.

According to a second aspect of the present invention, there is provided a variable resistance section, and a slider slidably contacting the variable resistance section and moving so as to change an output voltage from the variable resistance section by an external operation. In the rheostat, the variable resistance section includes a plurality of linear output areas where an output voltage from the variable resistance section changes linearly when a slider slides on the variable resistance section, and an output from the variable resistance section. It is intended to include a constant output region where the voltage is constant.

Therefore, according to the second aspect of the present invention, in each of the plurality of linear output regions, the output voltage from the variable resistor changes linearly. On the other hand, in the constant output region, the output voltage from the variable resistor becomes constant.

[0021] The invention of claim 3 is claim 1 or claim 2.
In the invention described in (1), the variable resistance portion is formed so that the sliding distance of a slider that is moved by an external operation is increased and the sliding distance of the slider is reduced. The gist is to include resistance.

Therefore, according to the third aspect of the present invention, in addition to the operation of the first or second aspect of the present invention, the slider is provided with a resistor formed so that the sliding distance of the slider becomes longer. The range of voltage change is wide in the sliding range, and the range of voltage change is small in the range in which the slider slides on a resistor formed such that the sliding distance of the slider is short.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the variable resistance portion is disposed on a circle having a predetermined radius of curvature on the substrate. ,
The gist is that the slider is moved by an external operation so as to draw an arc-shaped locus along the variable resistance portion.

Therefore, according to the invention of claim 4, in addition to the function of the invention of any one of claims 1 to 3,
When the slider slides on each resistor and each conductor while moving so as to draw an arc-shaped locus by an external operation, the output voltage changes according to the operation angle. That is, in the operation angle range in which the slider slides on the resistor, the output voltage changes according to the resistance value of the sliding contact position, and in the operation angle range in which the slider slides on the conductor, the output voltage is It will be constant.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the rheostat 1 includes a PC board 2, an operation member 3, and a cover 4. As shown in FIG. 2, the PC board 2 as a substrate has a resistance mounting portion 11 as a disc-shaped variable resistance portion.
And a connection portion 12 extending from the resistance mounting portion 11. A circular fitting hole 11a is formed at the center of the resistance mounting portion 11. A pair of mounting portions 13 and 14 are formed on an outer peripheral portion of the resistance mounting portion 11. The mounting section 13 has notches 15 to 17, and the mounting section 14 has a notch 18.
~ 20. The cover 4 is mounted on the mounting portions 13 and 14.

The cover 4 has a closed cylindrical shape having an outer diameter substantially equal to the diameter of the resistance mounting portion 11. And
Notch 1 of the resistance mounting portion 11 at the outer peripheral portion of the cover 4
Fixing claws 21 to 26 are provided at positions corresponding to 5 to 20. The fixing claws 21 to 26 are fitted into the cutouts 15 to 20, and the fixing claws 21, 23, 24, 26 are L inward.
The cover 4 is integrally fixed to the PC board 2 by being bent in a letter shape. The fixing claws 22, 2
Reference numeral 5 is attached and fixed to a light control board (not shown). A circular through hole 27 is formed on the upper surface of the cover 4.
The operation member 3 is accommodated in the cover 4.

As shown in FIG. 3, the operating member 3 has a base 31.
And an operation knob 32 protruding upward from the center of the upper surface of the base 31 and an engaging portion 33 (see FIG. 4) protruding downward from the center of the lower surface of the base 31. . As shown in FIG. 4, the outer diameter of the base 31 is
The diameter of the through hole 27 is larger than that of the base 31.
Is in contact with the periphery of the through hole 27 on the inner top surface of the cover 4. In addition, a pair of mounting protrusions 40 (only one is shown in FIG. 4) protrude from the lower end of the base 31. Then, the conductive sliding member 41 is mounted on the both mounting protrusions 40, and the two mounting protrusions 40 are melted, so that the sliding member 41 and the both mounting protrusions 40 are fused. .

The sliding member 41 slides on the PC board 2 and includes first and second sliding portions 42 and 43 (see FIG. 5) which are located approximately 180 degrees opposite to each other with the locking portion 36 interposed therebetween. Have. The first sliding portion 42 has elasticity, and the locking portion 3
Sliders 42a, 42 spaced apart from each other in the circumferential direction of 6
b. On the other hand, the second sliding portion 43 has elasticity, and includes sliders 43a and 43b arranged radially from the center of the locking portion 36. The sliders 43a, 4
3b, passes through the center of the shaft portion 37, and slides 42a, 42b
The imaginary line passing between them is hereinafter referred to as an operation line P.

The operating knob 32 has a cylindrical fitting portion 34 having a diameter substantially the same as the diameter of the through hole 27, and extends upward from the fitting portion 34, and a part of the cylinder is cut. Operation unit 35. The fitting portion 34 is fitted in the through hole 27, the upper end surface of the fitting portion 34 and the upper surface of the cover 4 are substantially flush, and the entire operation portion 35 projects from the upper surface of the cover 4. ing. The operation unit 35 can be operated from outside.

The engaging portion 33 includes a locking portion 36 having a large diameter and a shaft portion 37 having a small diameter. The locking step 36a of the locking portion 36 is formed around the fitting hole 11a on the upper surface of the PC board 2. And the shaft portion 37 is fitted in the fitting hole 11a. As a result, the operating member 3 is rotatable around the fitting hole 11a on the PC board 2, and the first and second sliding portions 42, 43
It slides on the board 2.

As shown in FIG. 2, a mounting hole 5 is provided at an end of a portion of the PC board 2 corresponding to the connection portion 12.
2 to 54 are formed at equal intervals. The mounting holes 52-
54 are provided with first to third connection terminals 55 to 57. The first to third connection terminals 55 to 57 are connected to the dimming control board by soldering or the like. That is, the first to third connection terminals 55 to 57 are electrically connected to a dimming control circuit provided on the dimming control board.

On the surface of the portion of the PC board 2 corresponding to the resistor mounting portion 11, first to fourth resistors 61 to 64 constituting resistors are formed on the same circle around the fitting hole 11a. Are printed apart from each other, and the second to fourth conductors 66 to 6 each constituting a conductor are printed.
8 are printed on the same circle. The circle constitutes a circle having a predetermined radius of curvature. In the present embodiment, first to fourth resistors 61 on the PC board 2
64 are printed apart from each other, and each resistor 61
The second to fourth conductors 66 to 68 for electrically connecting the resistors 61 to 64 are printed on the ends of the first to fourth conductors.

In the present embodiment, the first, second and fourth
Starting ends of the resistors 61, 62, and 64 (the first connection terminal 5
The electrical resistance from the fifth side to the end (third connection terminal 57 side) is R1 (each of which forms a predetermined resistance).
It has been. Also, the starting end (the first end) of the third resistor 63
The electrical resistance from the connection terminal 55 side to the terminal end (the third connection terminal 57 side) is seven times R1 (constituting a predetermined resistance value).
It has been.

In this embodiment, the first, second, and fourth resistors 61, 62, and 64 each constitute a resistor formed so that the sliding distance of the slider becomes short. Also, the third
The resistor 63 constitutes a resistor formed so that the sliding distance of the slider becomes long.

Further, each of the first to fourth resistors 61 to 64 is configured such that the electric resistance value from the starting end to the position linearly increases toward the end position. That is,
For example, in the case of the third resistor 63, the electric resistance value at the start end is 0.
The electric resistance from the starting end to the midpoint between the starting end and the end is 3.5 times R1 and the electric resistance from the starting end to the end is 7 times R1.

A first conductor 65 is printed on the PC board 2 over the first connection terminal 55 and the first resistor 61, and the first conductor 65 is connected to the first connection terminal 55 and the first resistor 61. 6
1 is electrically connected. The second conductor 66 includes a first resistor 61 and a second resistor 62, the third conductor 67 includes a second resistor 62 and a third resistor 63, and the fourth conductor 68 includes a third resistor. 63 and the fourth resistor 64 are electrically connected. Further, a fifth conductor 69 is printed on the PC board 2 over the fourth resistor 64 and the third connection terminal 57, and the fifth conductor 69 is connected to the fourth resistor 64 and the third connection terminal 57. Are electrically connected.

The first conductor 65 is connected to the first connection terminal 5.
5 and a curved portion 65b provided on an imaginary circle formed by the first to fourth resistors 61 to 64 and the like. On the other hand, the fifth conductor 69 has a straight portion 69a electrically connected to the third connection terminal 57 and a curved portion provided on an imaginary circle formed by the first to fourth resistors 61 to 64 and the like. 69b.

The sixth conductor 70 is provided on the surface of the PC board 2.
Is printed. The sixth conductor 70 is connected to the second connection terminal 56.
And a ring portion having a diameter smaller than an imaginary circle formed by the first to fourth resistors 61 to 64 and the like. And a ring portion 72. The first sliding portion 42 of the sliding member 41 provided on the operation member 3 slides on the ring portion 72, and the second sliding portion 43 is connected to the first to fourth resistors 61 to 64. , First and fifth conductors 6
5, 69 curved portions 65b, 69b, second to fourth conductors 66
６８68. That is, the second
The sliding portion 43 moves so as to draw an arc-shaped locus along a virtual circle formed by the first to fourth resistors 61 to 64 and the like. In FIG. 4, the second sliding portion 43 of the sliding member 41 is in contact with the third resistor 63.

The dimming control circuit includes the second sliding portion 43
When a voltage between the first connection terminal 55 and the second connection terminal 56 based on the contact position is input, based on the voltage,
On / off control of an illumination lamp (a plurality of lamps such as a room lamp) in a vehicle or dimming control of a dimming lamp is performed. The dimming lamp is used for illuminating instruments such as an automobile speedometer and switches such as an air conditioner switch.

Next, the operation of the rheostat 1 configured as described above will be described with reference to FIGS. FIG.
6 is a characteristic diagram showing a relationship between the operation angle θ of the rheostat 1 and the voltage ratio V. FIG.

First, the operation angle θ of the operation knob 32 when the operation line P of the operation knob 32 is arranged on the reference line L0 shown in FIG. Here, the reference line L0 corresponds to the center O of the fitting hole 11a of the PC board 2 and the curved portion 6 of the first conductor 65.
5b is a straight line passing through the start end. In FIG. 7, the reference line L0
In the above, the position of the first sliding portion 42 is indicated by reference numeral Q0,
The position of the second sliding portion 43 is indicated by a symbol P0. In addition, actually,
The Q0 position indicates the position of the intermediate portion between the two sliders 42a and 42b of the first sliding portion 42, and the P0 position indicates the position of the intermediate portion between the two sliders 43a and 43b of the second sliding portion 43. Is shown.

The operation line P of the operation knob 32 is shown in FIG.
The operation angles θ of the operation knob 32 when arranged on the first to ninth virtual lines L1 to L9 shown in FIG. Here, the first to ninth virtual lines L1 to L9 are straight lines passing through the center O, the start and end of the first to fourth resistors 61 to 64, and the end of the curved portion 69b of the fifth conductor 69, respectively. It is. In FIG. 7, the positions of the first sliding portion 42 are indicated by reference numerals Q1 to Q9 on the first to ninth virtual lines L1 to L9,
The positions of the second sliding portions 43 are indicated by reference numerals P1 to P9. Actually, the positions Q1 to Q9 correspond to the two sliders 42 of the first sliding portion 42.
A position of an intermediate portion between the sliders a and 42b is shown, and positions P1 to P9 indicate positions of an intermediate portion between the two sliders 43a and 43b of the second sliding portion 43.

When the operation angle θ is 0, ie, the first
When the sliding portion 42 is in the Q0 position, the ring portion 72 of the sixth conductor 70 is
And the second sliding portion 43 is in the first position at the position P0.
When contacted with the conductor 65, the electrical resistance between the first connection terminal 55 and the second connection terminal 56 becomes substantially zero, and the voltage input to the dimming control circuit becomes zero.

Next, the operation knob 32 is operated in the CW direction shown in FIG. 1 so that the second sliding portion 43 slides on the curved portion 65b of the first conductor 65, and comes into contact at the position P1. When the operation angle θ becomes θ1, the electric resistance value at that time becomes approximately 0, and the voltage input to the dimming control circuit becomes 0. That is, even if the operation angle θ is displaced from 0 to θ1, the voltage input to the dimming control circuit remains 0.

Next, when the second sliding portion 43 slides on the first resistor 61 and comes into contact at the position P2 until the operation angle θ becomes θ2, the voltage input to the dimming control circuit is reached. Is V1. That is, when the operation angle θ is changed from θ1 to θ2, the voltage ratio V linearly changes from 0 to V1.
In the present embodiment, the voltage ratio V corresponding to the electric resistance value R1 from the start end to the end of the first resistor 61 is V1.

Next, the second sliding portion 43 slides on the second conductor 66, and comes into contact at the position P3, and the operation angle θ is reduced to θ.
When it becomes 3, the voltage ratio V becomes V1. That is, the operation angle θ
Is displaced from θ2 to θ3, the voltage ratio V remains at V1.

Next, when the second sliding portion 43 slides on the second resistor 62 and comes into contact at the position P4, and the operation angle θ becomes θ4, the voltage ratio V becomes V2. That is, when the operation angle θ is changed from θ3 to θ4, the voltage ratio V linearly changes from V1 to V2. In the present embodiment, the electric resistance value (R1 = 2 of R1) obtained by adding the electric resistance value R1 from the start end to the end of the first resistor 61 and the electric resistance R1 from the start end to the end of the second resistor 62. Times the voltage ratio V corresponding to V2
And

Next, the second sliding portion 43 slides on the third conductor 67 and is brought into contact at the position P5, and the operation angle θ becomes θ.
When it becomes 5, the voltage ratio V becomes V2. That is, the operation angle θ
Is displaced from θ4 to θ5, the voltage ratio V remains at V2.

Next, when the second sliding portion 43 slides on the third resistor 63 and comes into contact at the position P6, and the operation angle θ becomes θ6, the voltage ratio V becomes V3. That is, when the operation angle θ is changed from θ5 to θ6, the voltage ratio V linearly changes from V2 to V3. In this embodiment, the electric resistance R1 from the start end to the end of the first resistor 61, the electric resistance R1 from the start end to the end of the second resistor 62, the third resistance
The electric resistance value from the start end to the end of the resistor 63 (7 of R1)
The voltage ratio V corresponding to the electric resistance value (9 times R1) obtained by adding the above-mentioned value to the current resistance value is set to V3.

Next, the second sliding portion 43 slides on the fourth conductor 68 and is brought into contact at the position P7, and the operation angle θ becomes θ.
At 7, the voltage ratio V becomes V3. That is, the operation angle θ
Is displaced from θ6 to θ7, the voltage ratio V remains at V3.

Next, when the second sliding portion 43 slides on the fourth resistor 64 and comes into contact at the position P8 until the operation angle θ becomes θ8, the voltage ratio V becomes V4. That is, when the operation angle θ is changed from θ7 to θ8, the voltage ratio V linearly changes from V3 to V4. In this embodiment, the electric resistance R1 from the start end to the end of the first resistor 61, the electric resistance R1 from the start end to the end of the second resistor 62, the third resistance
The electric resistance value from the start end to the end of the resistor 63 (7 of R1)
The voltage ratio V corresponding to the electric resistance value (10 times R1) obtained by adding the electric resistance value R1 from the beginning to the end of the fourth resistor 64 is V4 (the voltage ratio V is 100%). .

Next, the second sliding portion 43 slides on the curved portion 69b of the fifth conductor 69, and comes into contact at the position P9.
When the operation angle θ becomes θ9, the voltage ratio V becomes V4. That is, even if the operation angle θ is displaced from θ8 to θ9, the voltage ratio V remains at V4.

The dimming control circuit includes a first connection terminal 55 and a second connection terminal 5 based on the contact position of the second sliding portion 43.
When a voltage between the lighting lamps 6 and 6 is input, on-off control of the lighting lamps in the vehicle (in the present embodiment, a plurality of lighting lamps A and B such as room lamps, both of which are not shown) based on the voltage, or Performs dimming control of the dimming lamp.

For example, when the operation angle θ is in the range of 0 to θ1 and the voltage ratio V is 0, the dimming control circuit turns off the dimming lamp. When the operation angle θ is in the range of θ2 to θ3 and the voltage ratio V is V1, the dimming control circuit turns on only the illumination lamp A.

Further, when the operation angle θ is in the range of θ4 to θ5 and the voltage ratio V is V2, the dimming control circuit
Dimming control is performed on the dimming lamp so that the brightness of the tuning dimming lamp becomes the darkest. More specifically, the dimming control circuit outputs a pulse having a preset duty ratio to a switching element such as a transistor, drives the dimming lamp with the switching element based on the duty ratio, and controls the dimming lamp. Control brightness. When the voltage ratio V is V2, a pulse having the smallest duty ratio is output to the switching element, and the dimming lamp is turned on in the darkest state.

Further, when the operation angle θ is in the range of θ6 to θ7 and the voltage ratio V is V3, the dimming control circuit controls the dimming lamp so that the brightness of the tuning dimming lamp becomes the brightest. Dimming control. In this case, a pulse having the largest duty ratio is output to the switching element, and the dimming lamp is turned on in the brightest state.

Here, when the operation angle θ is in the range of θ5 to θ6 and the voltage ratio V is linearly displaced from V2 to V3, the dimming control circuit sets the dimming lamp based on the value of the voltage ratio V. To control the brightness. More specifically, when the operation angle θ is θ5
As θ approaches θ6, that is, as the voltage ratio V increases, a pulse having a larger duty ratio is gradually output to the switching element, and the dimming lamp is lit based on the duty ratio so as to gradually become brighter. In the present embodiment, the range in which the voltage ratio V is from V2 to V3 is defined as the rheostat variable region. That is, the rheostat variable region is a region for controlling the dimming of the dimming lamp.

When the operation angle θ is in the range of θ8 to θ9 and the voltage ratio V is V4, the dimming control circuit turns on the dimming lamp in the brightest state and turns on the illumination lamp B. Let it.

In this embodiment, the operation angle θ is θ1 to θ
2. Each range of θ3 to θ4, θ5 to θ6, and θ7 to θ8 constitutes a linear output area. Moreover, the operation angles θ are 0 to θ1, θ2 to θ3, θ4 to θ5, θ6 to θ7,
Each range of θ8 to θ9 constitutes a constant output area.

Therefore, according to the present embodiment, the following effects can be obtained. (1) In the present embodiment, the range in which the voltage ratio V is constant (the operation angle θ is 0 to θ1, θ2 to θ3, θ4 to θ5, θ6 to
By providing θ7, θ8 to θ9, the range in which the voltage ratio V changes (the operation angle θ is θ1 to θ2, θ3 to
(the ranges of θ4, θ5 to θ6, and θ7 to θ8), the voltage change width can be widened.

(2) In the present embodiment, the electric resistance values from the start end to the end of the third resistor 63 are defined as the first, second and fourth electric resistances.
Since the electric resistance from the beginning to the end of each of the resistors 61, 62, and 64 is set to seven times, the second sliding portion 43 is connected to the third resistor 63.
The voltage change width can be widened in the range of sliding upward (the operation angle θ is in the range of θ5 to θ6). That is, the rheostat variable region can be widened.

(3) In this embodiment, the first to fourth resistors 61 to 64 and the second to fourth conductors 66 to 64 are provided on the PC board 2.
68 are arranged on the same circle, and the second sliding portion 4 of the sliding member 41
By moving 3 in such a manner as to draw an arc-shaped locus along the circle, the voltage change width can be widened in the relationship between the operation angle θ and the voltage ratio V. That is, in the relationship between the operation angle θ and the voltage ratio V, the operation angle range in which the voltage ratio V is constant (the operation angle θ is 0 to θ1, θ2 to θ3,
By providing θ4 to θ5, θ6 to θ7, and θ8 to θ9, the operation angle range in which the voltage ratio V changes (the operation angles θ are θ1 to θ2, θ3 to θ4, θ5 to θ6, θ7 to
In each range of θ8), the voltage change width can be widened.

(4) In this embodiment, resistors (first to fourth resistors 61 to 64) and conductors (second to fourth conductors 66 to 68) are alternately arranged on the PC board 2. Therefore, in the relationship between the operation angle θ and the voltage ratio V, the voltage ratio V
Is constant (the operation angle θ is 0 to θ1, θ2 to θ
3, each range of θ4 to θ5, θ6 to θ7, θ8 to θ9)
And the range in which the voltage ratio V changes (the operation angle θ is θ1 to θ
2, θ3 to θ4, θ5 to θ6, and θ7 to θ8) appear alternately. That is, by making the characteristic of the voltage ratio V with respect to the operation angle θ a step-like shape having a certain region,
The effects (1) to (3) are achieved.

(5) In the present embodiment, since the second sliding portion 43 has elasticity, the resistance (the first to fourth resistors 61 to 61)
64) and the conductors (second to fourth conductors 66 to 68), even if a step is formed, the elastic force of the second sliding portion 43 can surely make sliding contact with the resistance or the conductor.

The above embodiment may be modified as follows. (1) In the embodiment, the first on the PC board 2
The fourth to sixth resistors 61 to 64 are printed apart from each other, and the second to fourth conductors 66 to 68 for electrically connecting the respective resistors 61 to 64 are printed thereon. The vertical relationship between the fourth resistors 61 to 64 and the second to fourth conductors 66 to 68 may be reversed.

(2) In the above embodiment, the first to fourth resistors 61 to 64 and the second to fourth conductors 66 to 68 are arranged on the same circle, and the ring portion 72 of the sixth conductor 70 is Although arranged above, each resistor 61-64 and each conductor 66-
68 may be arranged on the same polygon such as a triangle, a quadrangle or a pentagon, and a part of the sixth conductor 70 may be arranged on a polygon similar to the polygon. In this case, the sliding member 41
The first and second sliding portions 42 and 43 are moved so as to draw polygonal trajectories along the respective polygonal shapes.

The resistors 61 to 64 and the conductors 66 to 64
68 may be arranged on the same straight line, and a part of the sixth conductor 70 may be arranged on a straight line parallel to the straight line. In this case, the first and second sliding portions 42 and 43 of the sliding member 41 are moved so as to draw linear trajectories along the straight lines parallel to each other.

(3) In the above-described embodiment, five fixed output area portions (operating angles θ of 0 to θ1, θ2 to θ3, θ4 to
θ5, θ6 to θ7, and θ8 to θ9).
It may be a part. In this case, there are two linear output area portions (in the embodiment, the operation angles θ are θ1 to θ2, θ3
To θ4, θ5 to θ6, and θ7 to θ8).

Next, technical ideas other than those described in the claims which can be understood from the embodiment and other examples will be described below together with their effects. (A) The rheostat according to claim 1, wherein the variable resistance portion has a configuration in which resistors and conductors are alternately arranged.

Therefore, according to the invention described in (a), the range in which the output voltage is constant (the range in which the slider slides on the conductor) and the range in which the output voltage changes (the slider is And the range of sliding on the resistor) appear alternately. That is, the effect of the invention described in claim 1 is achieved by making the voltage characteristic a stepped shape having a certain area.

(B) The rheostat according to claim 2, wherein the variable resistance section includes a plurality of constant output area sections. Therefore, according to the invention described in (b), the output voltage is stepped by the plurality of linear output regions and the plurality of constant output regions, thereby achieving the effect of the invention described in claim 2. .

[0072]

According to the first aspect of the present invention, the range in which the output voltage is constant (the range in which the slider slides on the conductor)
Is provided, the voltage change width can be widened in a range where the output voltage changes (a range where the slider slides on the resistor).

According to the second aspect of the present invention, by providing the constant output region, the voltage change width can be widened in each linear output region. According to the third aspect of the present invention, in addition to the effects of the first or second aspect of the present invention, in addition to the resistance of the slider formed such that the sliding distance of the slider becomes longer. In the sliding range,
The voltage change width can be widened.

According to the fourth aspect of the present invention, in addition to the effect of the first aspect of the present invention, in addition to the operation angle range (sliding) in which the output voltage is constant. Operation angle range in which the child slides on the conductor)
In the operation angle range where the output voltage changes (the operation angle range in which the slider slides on the resistor), the voltage change width can be widened.

[Brief description of the drawings]

FIG. 1 is a perspective view of a rheostat according to an embodiment.

FIG. 2 is a plan view showing a PC board.

FIG. 3 is an exploded perspective view of the rheostat.

FIG. 4 is a sectional view taken along line AA in FIG. 1;

FIG. 5 is a bottom view of the operation member.

FIG. 6 is a characteristic diagram showing a relationship between an operation angle of a rheostat and a voltage ratio.

FIG. 7 is a plan view of the PC board showing a contact position of a sliding member on the PC board.

FIG. 8 is a plan view showing a PC board of a conventional rheostat.

FIG. 9 is a characteristic diagram showing a relationship between an operation angle of a conventional rheostat and a voltage ratio.

[Explanation of symbols]

1 ... rheostat, 2 ... PC board as substrate, 11
... Resistor mounting part as variable resistance part, 43a ... Slider, 4
3b: a slider; 61: a first resistor as a resistor (constituting a resistor formed so as to reduce the sliding distance of the slider); 62 ... a second resistor (slider) as a resistor And a resistor formed so as to reduce the sliding distance of the child.),
63... A third resistor as a resistor (constituting a resistor formed so as to increase the sliding distance of the slider); 64... A fourth resistor as a resistor (the sliding distance of the slider A resistor formed so as to be shorter) 66, a second conductor as a conductor, 67 a third conductor as a conductor, 68 a fourth conductor as a conductor.

Claims (4)

[Claims] 1. A rheostat comprising: a variable resistance portion; and a slider slidably contacting the variable resistance portion and moving so as to change an output voltage from the variable resistance portion by an external operation. The resistance portion includes a plurality of resistors having a plurality of predetermined resistance values and a conductor electrically connected between the resistors, and the slider includes a conductor provided between the resistors, and a resistor. A rheostat characterized in that it slides including it. 2. A rheostat, comprising: a variable resistance portion; and a slider slidably contacting the variable resistance portion and moving so as to change an output voltage from the variable resistance portion by an external operation. The resistance section has a plurality of linear output areas where the output voltage from the variable resistance section changes linearly when the slider slides on the variable resistance section, and the output voltage from the variable resistance section becomes constant A rheostat comprising a constant output area. 3. The variable resistance section includes a resistor formed so that a sliding distance of a slider that is moved by an external operation is increased, and a resistor formed such that the sliding distance of the slider is shortened. The rheostat according to claim 1, comprising: 4. The variable resistance section is disposed on a circle having a predetermined radius of curvature on a substrate, and the slider draws an arc-shaped locus along the variable resistance section by an external operation. The rheostat according to any one of claims 1 to 3, wherein the rheostat is configured to move.